Drum-mix plants

In a drum-mix plant, the aggregate material is heated and mixed with the bitumen in the same rotating drum, known as the drum mixer. Drum-mix plants are also known as continuous-flow plants hence, the provision of storage bins is essential. 

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Both batch and drum mixing plants have been used on SEA pavement construction projects throughout the United States,... 

In drum-mix plants, the mixing of the aggregate and the bitumen takes place in the dryer/ heater drum, after which the asphalt is stored in a silo (or silos) before being loaded into delivery trucks. 

Today, the predominant plant in the United States and New Zealand is the drum-mix plant. Batch plants prevail in Europe, South Africa and Australia (EAPA and NAPA 2011). 

The basic disadvantages of a conventional batch plant are as follows high capital cost, relative high maintenance cost, overall higher production cost over drum-mix plants, heat and aggregate material wasted on overflow material and capacity being restricted to mixing cycle and mixer size. 

Figure 8.2 Typical layout of parallel-flow drum-mix plant for hot mix asphalt. (From EAPA and NAPA, The Asphalt Paving Industry A Global Prospective, 2nd Edition, GL 101. Brussels EAPA, 2011 Courtesy of National Asphalt Pavement Association, http //www.asphaltpavement.org.)...

In general, a drum-mix plant is relatively simple and smaller in size than a batch plant. Regarding the hourly output, it may reach up to 500-550 tonnes per hour. Thus, this type of plant is considered as the most appropriate in cases of high demand. 

The other advantages of the parallel-flow drum-mix plant are as follows lower capital cost in comparison to batch plant, lower space requirement, higher outputs can be achieved,... 

All the other production stages are exactly the same as those in the parallel-flow drum-mix plant. 

The basic advantages of a counterflow plant over a parallel-flow drum-mix plant are that it is more environment friendly, fuel efficiency increases and higher percentages of reclaimed asphalt can be used. 

Mixing is carried out in hot mixing batch plants or drum-mixing plants capable of incorporating RA. Details on hot mixing plants can be found in Section 8.2. 

Blending System Paddle Mixer And Pelletiser Mixing Plant - Conditioning Drumj Mixing Drum Pelletizer Disc ... 

Certain refinery wastewater streams are treated separately, prior to the wastewater treatment plant, to remove contaminants that would not easily be treated after mixing with other wastewater. One such waste stream is the sour water drained from distillation reflux drums. Sour water contains dissolved hydrogen sulfide and other organic sulfur compounds and ammonia which are stripped in a tower with gas or steam before being discharged to the wastewater treatment plant. 

A drum of these two, apparently freshly mixed as feed for a reaction, pressurised and exploded. The subsequent fire destroyed the plant and injured 31 people. Styrene is polymerisable and the two probably react by Friedel-Crafts type chemistry, if suitably catalysed. It is not reported whether the drum was lined, plain steel, or galvanised. 

Mixed liquor from a municipal WW treatment plant Acid orange 8 Acid orange 10 Acid red 14 Rotating drum biofilm reactor Continuous Aerobic B Drum 22 7... 

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